This invention pertains to microfilm cameras having a electronic logic elements for correlating operation.
U.S. Pat. No. 3,007,368, to Rosenblum in 1961, discloses only a vacuum platen. Film is moved across the platen by other means and only when an exposure is to be made is vacuum applied, thus stopping and flattening the film. This is important for the large film used for aerial photography illustrated by Rosenblum.
U.S. Pat. No. 3,339,815, to Fredkin in 1967, discloses a computer-controlled film indexing device for high speed film reading or recording, typically of an image upon a cathode-ray tube. Stepper motors are computer controlled.
U.S. Pat. No. 4,007,889, to Langford in 1977, discloses an all-mechanical film flow camera in which the film is moved by an intermittently operated capstan, to record an image while the film is moving.
U.S. Pat. No. 3,197,645, to Sperry in 1965, discloses a loop-sensing apparatus in which photoelectric means act as sensors to determine the length of a film loop in a chamber and provide data for the control of the length thereof.
U.S. Pat. No. 3,767,302, to Roberts et al in 1973, discloses principally a wide-film microfiche camera having a vacuum platen and air blow-off for film movement, only one film loop chamber, and microprocessor control of the opto-mechanical element